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Biomedical subjects

A Albertini

Publications and source records attributed to A Albertini.

At least 181 records · Page 10Linked to original sources
PubMed1985

Oxygen-mediated myocardial damage during ischaemia and reperfusion: role of the cellular defences against oxygen toxicity.

The possibility that myocardial ischaemia alters the defence mechanisms against oxygen toxicity has been investigated. Ischaemia was induced in isolated, perfused rabbit hearts by reducing coronary flow from 25 ml/min to 1 ml/min for 90 min. Two different degrees of ischaemic damage have been achieved using either spontaneously beating or electrically stimulated hearts. The effects of post-ischaemic reperfusion were also followed for 30 min. Tissue activity of superoxide dismutase (SOD), glutathione peroxidase and reductase (GPD and GRD) have been determined together with tissue content of reduced and oxidized glutathione (GSH and GSSG) and of protein SH groups. The changes in myocardial ATP and CP content and release of CPK and of GSH and GSSG were also determined. Systolic and diastolic pressures were continuously monitored. In the spontaneously beating hearts ischaemia induced a reduction of tissue GSH and protein SH groups. On reperfusion there was a recovery of mechanical function, a transient release of GSH into the coronary effluent and an increase of tissue GSH. In the paced hearts, ischaemia resulted in 50% reduction of mitochondrial SOD activity together with a reduction of tissue GSH and protein SH groups. Reperfusion induced a massive release of CPK and of GSH and GSSG, a further reduction of tissue GSH concomitant with an increase of GSSG and no recovery of mechanical function. GPD and GRD activity were not affected by ischaemia and reperfusion. These data indicate that severe ischaemia induces a reduction of the protective mechanisms against oxygen toxicity.

Adenosine Triphosphate↗
PubMed1985

Evaluation of valproic acid fluoroimmunoassay and comparison with a gas liquid chromatographic method.

A method for monitoring valproic acid in serum with a fluoroimmunoassay is described. The evaluation was performed with run-to-run and within-run reproducibility, dilution, and recovery tests. The interferences of hemoglobin, bilirubin, and triglycerides were checked, and a comparison with a gas liquid chromatographic method was also performed. The between-run and within-run coefficients of variation were less than 5.2 and 2.6%, respectively. The method gave satisfactory results in dilution tests and a high correlation with a gas liquid chromatographic method (r = 0.98). The percentage of recovery was greater than 97%. No interference from hemolysis, bilirubin, or triglycerides was observed. The accuracy and simplicity of this method make it suitable for routine laboratory use.

Bilirubin↗
PubMed1985

HBeAg/anti-HBe determination with a new monoclonal immunoradiometric assay.

The performance of two assays for the HBeAg/anti-HBe system associated with hepatitis B virus infection, using monoclonal (EBK-Sorin) and polyclonal (HBe-Abbott) antibodies, has been compared. The results on a random population (1,000 samples) demonstrated for the monoclonal reagent a higher sensitivity, without any loss in specificity, and with the further advantage of the use of lower radioactivity levels. The proportion of positives and negatives obtained with the two kits was found to remain unchanged in the case of HBeAg, while a markedly larger percentage of positives (7% higher) was detected for anti-HBe using the monoclonal antibodies.

Antibodies, Monoclonal↗
PubMed1985

Diagnosis of coronary artery disease by radionuclide ventriculography during stress: handgrip and cold pressor.

Radionuclide ventriculography during stress has been shown a useful and non invasive technique for detecting left ventricular dysfunction induced by ischemia in association with coronary artery disease. The aim of this study was to assess the usefulness of handgrip and cold pressor test as alternative stresses because of the limits that bicycle exercise presents when it is combined with multigated radionuclide ventriculography. A resting cardiac imaging was performed in 8 healthy volunteers and in 21 patients with coronary artery disease. All of them repeated the examination during handgrip; 6 controls and 11 patients also underwent cold pressor test. Abnormal regional wall motion was observed in 17 of the 21 patients with coronary artery disease who underwent handgrip, while all the controls maintained a normal motility. The test elicited no significant difference in average ejection fraction in both patients and normal subjects. All but one the patients who performed the cold pressor test showed an abnormal motility during the stress. Mean ejection fraction decreased significantly (p less than 0.05). All the controls had a normal response to cold pressor. Our results confirm that these two tests can be alternative to stress testing for detecting coronary artery disease by means of radionuclide ventriculography.

Adult↗
PubMed1984

Ejection fraction and regional wall motion at rest and during stress in the diagnosis of coronary artery disease.

Stress radio nuclide ventriculography is used to determine ejection fraction and changes in regional wall motion for the detection of ischemia-induced left ventricular dysfunction in patients with coronary artery disease. We have evaluated the relative sensitivity of regional wall motion and of ejection fraction during hand-grip and cold pressor test, in 21 patients with angina pectoris and documented coronary artery disease at angiography. Regional wall motion appeared a more sensitive index than global ejection fraction producing only two false negative cases. Ejection fraction showed great variability among the patients during both hand-grip and cold pressor test. This might be explained by the fact that both tests do not produce a sufficient degree of ischemic stress on the left ventricle. Hand-grip and cold pressor tests appear useful alternative to dynamic exercise in the diagnosis of coronary artery disease being also safe and simple to perform.

Adult↗
PubMed1984

Reversible and irreversible ischaemic damage: importance of energy metabolism.

In this study the effects of different degrees and duration of coronary flow reduction on pressure development of the isolated and perfused rabbit hearts has been studied. Three different degrees of ischaemia lasting for 30, 60 and 90 minutes have been investigated, after which the effects of post-ischaemic reperfusion have been followed. The effects of substituting FFA for glucose as myocardial substrate has also been investigated. Reperfusion resulted in a recovery of mechanical function or in a further worsening of mechanical function, depending upon the degree, duration of flow reduction and substrate employed. To establish the causes of reperfusion damage, in a separate series of experiments the effects of reperfusion after 90 minutes of severe ischaemia on lactate, CPK and Mg++ release, tissue and mitochondrial calcium content tissue ATP and CP concentration and mitochondrial function have been determined. The ultrastructural damage of the myocardial cell have also been established. The results obtained suggest that mitochondria play an important role in reperfusion damage.

Adenosine Triphosphate↗
PubMed1984

Use of a reference standard to improve the accuracy and precision of seven kits for determination of ferritin in serum.

We assessed the accuracy and precision of seven commercial kits for serum ferritin. The concentration of ferritin as determined by these assays for a liver ferritin reference standard, a human heart ferritin standard, and normal sera correlated highly, but the absolute values varied widely. Use of an international reference standard for ferritin to prepare the standard curve greatly diminished the variability, but did not eliminate it. Although the seven kits differed in specificity for various human isoferritins, this did not appear substantially to affect accuracy. Six of the seven kits appeared sufficiently precise for clinical use over a wide range of ferritin concentrations.

Ferritins↗